Does mandibular advancement with clear aligners have the same skeletal and dentoalveolar effects as traditional functional appliances?

BACKGROUND: The study aimed to compare the dentoskeletal effects of Vanbeek Activator, Herbst, Twin-Block and Mandibular Advancement with clear aligners in children with skeletal Class II malocclusions. METHODS: A sample with sixty-three patients (37 males, 26 females) was included and divided into untreated control group (C, n = 12), Vanbeek Activator group (V, n = 14), Herbst group (H, n = 11), Twin-Block group (TB, n = 12) and MA group (MA, n = 14). Cephalometric analysis and Johnston Pitchfork analysis were performed to quantify the skeletal and dentoalveolar components in molar relationship and overjet correction. Compare the differences of cephalometric data and Johnston-analysis data. RESULTS: The treatment changes showed significant differences in SNB, FH-NP, NA-PA, Co-Go, Co-Pog, ANB, lower facial height ratio, U1-PP, U6-PP, L1-MP and U1-L1. All the appliances improved overjet relationships significantly (Vanbeek, Herbst, Twin-Block and MA were 2.77 mm, 5.53 mm, 4.73 mm and 3.66 mm respectively) with significant retraction of maxillary incisors. The lower incisor displacement of group V and MA was negative, while that of group H and TB was positive and there were significant differences. Molar relationships were also improved by 3.45 mm, 6.85 mm, 3.48 mm and 0.92 mm for Vanbeek, Herbst, Twin-Block and MA. Mandible displacement showed a trend of group H > TB > V > MA. The displacement of maxillary molars in group H was greater than that in group C, TB and MA, and that of mandibular ones was greater than that in group C, V and MA, significantly. Herbst, Twin-Block and MA have more significant dentoalveolar effect than Vanbeek, while Vanbeek has more skeletal effect than the others especially in restraining maxillary growth. CONCLUSIONS: Four appliances are all effective in mandibular advancement, modification of class II molar relationship and deep overjet, with unavoidable increase in lower facial ratio. Vanbeek Activator has the most skeletal effects. Vanbeek and MA have a good control of mandibular incisors while more compensatory lower incisors proclination in Herbst and Twin-Block. Herbst has greater maxillary molar distalization. MA allows aligning and leveling meanwhile leading the mandible forward.

Temporomandibular joint changes after activator appliance therapy: a prospective magnetic resonance imaging study.

The aim of this prospective clinical and magnetic resonance imaging study was to analyze the effect of 1-year Activator (Yi-fan Dental Co., Shanghai, China) treatment in internal anatomical relationships of the temporomandibular joint (TMJ) complex, including the condyle-disc relationship, condyle-fossa relationship, condylar height change, disc length change, and morphologic change of the glenoid fossa. The study was composed of patients with class II division 1 malocclusion (11 girls and 13 boys) who underwent 1-year Activator treatment. All the patients were in the acceleration or peak phase of the pubertal growth spurt. Magnetic resonance imaging in closed-mouth position and lateral cephalometric radiographs before and after 1 year of Activator treatment were analyzed metrically. Overall, condylar height showed a significant increase (P < 0.001), and the eminence angle decreased (P = 0.037). TMJ disc length has no statistically significant change before and after treatment. A slight advancement (P = 0.041) was found in the sagittal condylar position. A significant backward movement (P = 0.04) was shown in the sagittal disc position. Our results showed that the disc is not impaired by Activator therapy; it seems possible that adaptive remodeling, including a shallower glenoid fossa and increased condylar height, was seen after treatment.

Bone grafting, corticotomy, and orthodontics: treatment of cleft alveolus in a chinese cohort.

Objective : A multimodal therapy was applied to solve a set of related problems including collapse of the posterior segment, high level gingival margin of canine, and resorption of grafted bone in a cohort of Chinese youngsters with cleft lip and palate. This study aimed to evaluate the benefits of this treatment procedure. Methods : Thirty patients with unilateral cleft lip and palate were included in this prospective study. All patients had previously undergone only cleft lip and palate repair and presented with alveolar cleft and an obvious step in the gingival margin between the canine tooth and the teeth beside it. A multimodal therapy that included bone grafting, corticotomy, and orthodontics was applied to solve these problems. Grafted bone volume, parallelism of the roots, root resorption, gingival margin, and mobility of the canine on the cleft side were established before surgery, 1 week after surgery, and after straightening of the canine. Results : Less than 25% of the grafted bone was reabsorbed in 25 of the 30 patients, while less than 50% was resorbed in the remaining five. The roots of the canines on the cleft side were mostly parallel to the adjacent teeth. Root resorption and mobility of the canines were slight. The difference in the gingival margin between the canines on the cleft side and the other side was small. Conclusions : Canines moved into the grafted bone safely and effectively, thus achieving a normal gingival margin and retaining grafted bone volume in one operation.

Melatonin Engineering M2 Macrophage-Derived Exosomes Mediate Endoplasmic Reticulum Stress and Immune Reprogramming for Periodontitis Therapy.

Periodontitis is a chronic infectious disease caused by bacterial irritation. As an essential component of the host immunity, macrophages are highly plastic and play a crucial role in inflammatory response. An appropriate and timely transition from proinflammatory (M1) to anti-inflammatory (M2) macrophages is indispensable for treating periodontitis. As M2 macrophage-derived exosomes (M2-exos) can actively target inflammatory sites and modulate immune microenvironments, M2-exos can effectively treat periodontitis. Excessive endoplasmic reticulum stress (ER stress) and unfolded protein response (UPR) are highly destructive pathological characteristics during inflammatory periodontal bone loss. Although melatonin has antioxidant and anti-inflammatory effects, studies focusing on melatonin ER stress modulation remain limited. This study fabricates engineered M2-exos loading with melatonin (Mel@M2-exos) for treating periodontitis. As a result, M2-exos drive an appropriate and timely macrophage reprogramming from M1 to M2 type, which resolves chronic inflammation and accelerated periodontal healing. Melatonin released from Mel@M2-exos rescues the osteogenic and cementogenic differentiation capacity in inflammatory human periodontal ligament cells (hPDLCs) by reducing excessive ER stress and UPR. Injectable gelatin methacryloyl (GelMA) hydrogels with sustained-release Mel@M2-exos accelerate periodontal bone regeneration in rats with ligation-induced periodontitis. Taken together, melatonin engineering M2 macrophage-derived exosomes are promising candidates for inflammatory periodontal tissue regeneration.

Three-D imaging of dental alveolar bone change after fixed orthodontic treatment in patients with periodontitis.

OBJECTIVES: The objective of this study was to radiographically quantify bone height and bone density in patients with periodontitis after fixed orthodontic treatment using cone beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 81 patients including 40 patients with chronic periodontitis (group 1) and 41 patients with normal periodontal tissues (group 2) were selected. CBCT scanning for anterior teeth were taken before and after orthodontic treatment. Measurements of bone height and bone density were performed using CBCT software. RESULTS: The group 1 presented a statistically lesser bone density and bone height when compared to group 2 before treatment. There was a significant loss of bone density for both groups after orthodontic treatment, but bone density loss was significantly greater in the group 1. There was no statistically significant bone height change in two groups after treatment. CONCLUSIONS: This study demonstrated that orthodontic treatment can preserve bone height but not capable of maintaining bone density, especially for patients with periodontitis. It is indicated that the change of bone density may be more susceptible than that of bone height when radiographically evaluating bone status under this combined periodontal and orthodontic therapy.

[Measurement of alveolar bone thickness of adult skeletal Class III patients in mandibular anterior region].

PURPOSE: To describe alveolar bone thickness in mandibular anterior region of skeletal Class III malocclusion with the help of Cone-beam CT. METHODS: The subjects were selected from consecutive adult patients seeking orthodontic treatment in Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2008 to March 2011, which included 64 patients diagnosed to be skeletal Class I malocclusion (Class I group) and 66 patients diagnosed to be skeletal Class III malocclusion (Class III group). Both Class I and Class III groups were divided into 3 divisions respectively according to different vertical facial types. Mandibular left central incisor of each subject was chosen for measurement. The labial (L1), lingual (L2) and total (L0)alveolar bone thickness of skeletal Class III patients in mandibular anterior region were assessed using a CBCT analyzing method with Class I group as the control group. Data was processed with SAS8.02 software package. RESULTS: L1(P<0.05),L2(P<0.01) and L0(P<0.01) of Class III group were thinner than those of Class I group. L1 of high-angle Class III malocclusion was thinner than that of average-angle(P<0.01)and low-angle(P<0.01) ones ; L2 of average-angle Class III malocclusion was thinner than that of low-angle ones(P<0.01) and thicker than that of high-angle ones(P<0.05); L0 of low-angle Class III malocclusion was thicker than that of average-angle ones(P<0.01),which was thicker than that of high-angle ones(P<0.01). L1 of Class III group with different vertical facial types was thicker than L2(P<0.01). CONCLUSIONS: Skeletal Class III malocclusion exhibits thinner alveolus around the mandibular incisor apices compared with Class I malocclusion, which shows strong connection with different vertical facial types. Root apices of mandibular anterior teeth of skeletal Class III malocclusion situated closer to labial cortical bone than lingual cortical bone. It is necessary to access the alveolar bone thickness of adult skeletal Class III patients in mandibular anterior region before orthodontic camouflage or surgical-orthodontic treatment. Orthodontic camouflage might not be a reasonable treatment alternative for these patients.

[Clinical study of ramus implant anchorage for mandibular arch distalization].

PURPOSE: To evaluate the efficiency of ramus implant anchorage for mandibular arch distalization, and determine the feature of tooth movement. METHODS: Six patients were selected to distalize mandibular arch with ramus implant anchorage. Position changes of mandibular first molars and incisors were measured in sagittal and vertical direction to evaluate the amount of molar and incisor distalization and character of tooth movement. SPSS17.0 software package was used for statistical analysis. RESULTS: The average amount of distalization of mandibular first molar was 4.88mm at crown level and 3.1mm at root level, and of mandibular incisor was 5.02mm at crown level and 1.03mm at root level. All of the lower arches were distalized successfully and achieving normal overjet and overbite. CONCLUSIONS: Significant true distalization of lower arch could be obtained by ramus implant as bony anchorage. The method could be used to correct anterior cross bite and mandibular anterior crowding or flaring without extraction.

[Exploration on the sliding mechanism of implant anchorage assisted self-ligating appliance].

PURPOSE: To investigate non-extraction treatment of borderline cases through analysis of cases treated by maxillary implant anchorage assisted self-ligating appliance. METHODS: Twenty adult patients with moderate-crowding malocclusion were reviewed. The patients were divided into 2 groups. G1 group comprised 10 patients, 6 males, 4 females, aged 18-26 years(mean: 22 years old), treated by implant anchorage assisted self-ligating appliance; G2 group comprised 10 patients, 5 males, 5 females, aged 19-25 years(mean: 23 years old), treated by self-ligating appliance. Dental casts and lateral cephalometric radiographs were measured before and after orthodontic treatment (or after leveling and alignment). SAS8.02 software package was used for statistical analysis. RESULTS: Significant increase in inter-premolar arch width and inter-molar arch width were noted after orthodontic treatment or first treatment phase in both groups, with no significant difference between the G1 and G2 groups. No significant difference was observed in molar inclination within the treatment process in both groups. UI-SN and UI-NA increased significantly after orthodontic treatment or first treatment phase in two groups with statistical difference between the G1 and G2 groups, indicating that implant-anchorage contributed better control of the upper incisor. G1 also showed a statistically greater molar distal movement than G2. CONCLUSIONS: During the non-extraction treatment of borderline cases, maxillary implant-anchorage assisted self-ligating appliance can entirely retract the upper dental arch, expand the arch width and show better control of the upper incisor, so the fine naso-labial relationship, upper lip protrusion and soft-tissue profile can be maintained. Compared with headgear and pendulum, implant anchorage assisted self-ligating appliance is a better way to handle borderline cases with non-extraction approach.

Reconstruction of partial maxillary defect with intraoral distraction osteogenesis assisted by miniscrew implant anchorages.

OBJECTIVE: The paper reports a custom-made trifocal transport distractor assisted by miniscrew implant anchorages (MIAs) used to reconstruct maxillary defects and evaluates the clinical results of function and esthetics. STUDY DESIGN: Eight patients aged 19-43 years who suffered regional maxillary defects were involved. Each one underwent segmental bone excision of the maxilla and distraction osteogenesis (DO) in the defect region by a custom-made interoral 3-dimensional distractor which was activated by orthodontic elastic force assisted by MIAs at the rate of

[Cephalometric analysis of implant anchorage-assisted retraction of anterior teeth].

PURPOSE: The purpose of this study is to compare the different effects of alveolar bone remolding due to retraction of anterior teeth by two types of anchorage mini-screw implant or regular maximum anchorage. METHODS: The sample comprised 26 orthodontic patients with upper dental alveolar bone protrusion and mild crowding. The treatment plan was to remove the four first bicuspids. 14 patients,3 males,11 females, aged 20-54 years old (mean: 25 years) were treated with implant anchorage to retract the maxillary anterior teeth. 12 patients, 1 male,11 females, aged 18-30 years old (mean: 21 years) were treated with regular maximum anchorage to retract maxillary anterior teeth. Lateral cephalograms of all patients were evaluated at two stages: pretreatment, post-treatment.The changes of the long axis of the anterior teeth and dental alveolar were measured.SPSS11.0 software package was used for statistical analysis. RESULTS: The cephalometric findings showed that the anterior teeth were retracted with implant anchorage significantly more than the maximum anchorage, there was no significant difference in the dental alveolar bone remolding between two groups. The first molars moved anteriorly slightly (less than 1mm) with implant anchorage, but significantly (3.08 mm) with regular maximum anchorage. CONCLUSIONS: The maxillary anterior teeth are significantly retraced with the implant anchorage; the molars move mesially significantly less in the implant group than the maximum group. There are no significant differences in dental alveolar bone remolding between both groups. Support by Shanghai Leading Academic Discipline Project (Grant No.Y0203) and Research Fund of Science and Technology Committee of Shanghai Municipality (Grant No. 05B224).

[Clinical evaluation of implant anchorage for molar intrusion: report of the short-term results].

PURPOSE: The purpose of this study is to evaluate the efficiency and security of self-drilling mini-screw implant anchorage for molar intrusion, to achieve the right position of the mini-screw implant. METHODS: Ten patients with overerupted maxillary molars were selected, aging from 25 to 53 years old, the average age was 33 years old. There were 2 men and 8 women. All the overerupted molars were intruded in gingival direction with mini-screw implants anchorage. RESULTS: The mean intrusive movement of the overerupted maxillary molars was 3 mm, the mean treatment time were 3.5 months.All of the missing teeth were treated by prosthetic treatment. No obvious root resorption, pulp necrosis and tooth loosen were found. CONCLUSIONS: Significant true intrusion of maxillary molars could be obtained by mini-screw implant as bony anchorage.Supported by Shanghai Leading Academic Discipline Project (Grant No.Y0203) and Research Fund of Science and Technology Committee of Shanghai Municipality (Grant No.05B224).